Method of operating a submersible barge for submarine operations



Sept. 13, 1966 P. A. WOLFF 3,271,964

METHOD OF OPERATING A SUBMERSIBLE BARGE FOR SUBMARINE OPERATIONSOriginal Filed Oct- 21, 1955 6 Sheets-$heet l INVENTOR PAUL A. WOLFF BYQSW ATTORNEYS METHOD OF OPERATING A SUBMERSIBLE BARGE FOR SUBMARINEOPERATIONS Original Filed Oct. 21, 1955 e Sheets-Sheet z FIG. 3 f 20ATTORNEYS Sept. 13, 1966 P. A. WOLFF 3,2 ,96

METHOD OF OPERATING A SUBMERSIBLE BARGE FOR SUBMARI Original Filed Oct.21, 1955 NE OPERATIONS 6 Sheets-Sheet 4 8/ PAUL A WOLFF ATTORNEYS FIG. 718 Sept. 13, 1966 P. A. WOLFF 3,271,964

METHOD OF OPERATING A SUBMERSIBLE BARGE FOR SUBMARINE OPERATIONSOriginal Filed Oct. 21, 1955 6 Sheets-Sheet 5 FIG. 20 F 6. 2/

I /80 l z f E l9 10 /a /9 /0 /a g /42 I L INVENTOR PAUL A. WOLFF FIG. /3

BY -4W ATTORNEYS Sept. 13, 1966 P. A. WOLFF 3,271,964 METHOD OFOPERATING A SUBMERSIBLE BARGE FOR SUBMARINE OPERATIONS Original FiledOct. 21, 1955 6 Sheets-Sheet 6 I65 80- FIG/5 BY M M 18 Fla 4 l0ATTORNEYS ited This is a division of application Serial No. 541,998filed October 21, 1955, now Patent No. 3,099,912.

This invention relates to improvements in submersible barges forsubmarine operations such as submersible barges designed for oft-shoredeep well drilling operations.

The prior art includes submersible barges adapted for submarineoperations, such as ofl-shore drilling operations, of the type includinga main structure adapted to carry equipment for submarine operations andhaving a hull, and relatively movable pontoons associated with the mainstructure for stabilizing the barge especially during submergence andrefloating operations. The hull and the stabilizing pontoons arecompartmented and means are provided for adding or removing waterballast from the compartments to control their buoyancy. The relativemovement required during su-bmergence and refloating operations betweenthe main structure and the pontoons is obtained by adding or removingballast, usually water, to or from the hull or pontoons, and in somecases flexible connections, such as wire ropes, are joined between therelatively movable main structure and the pontoons to control the rateof relative movement of the main structure or the pontoons only in onepredetermined direction.

Prior submersible barges, in which relative movement between the mainstructure and the pontoons is obtained by controlling their buoyancy,are limited to relatively shallow submarine operations, while the typeof prior submersible barges including flexible connections between therelatively movable main structure and pentoons, although capable of deepsubmarine operations, are subject to serious instability problems whenoperating in bad weather, as in the presence of heavy swells or highwinds, for example.

The present invention provides a novel submersible barge, and novelmethod of operating the same, capable of deep water submarine operationswhile providing a high degree of stability, even in the presence ofunfavorable weather conditions.

According to the present invention, there is provided a submersiblebarge including a main structure or section having a hull and astabilizing pontoon section. The pontoon section is mounted for relativemovement with respect to the hull to different positions along apredetermined path including a first position in which the center ofdisplacement of the pontoon section is close to the center ofdisplacement of the hull, a second position in which the center ofdisplacement of the pontoon section is displaced above the center ofdisplacement of the hull and to successive positions between the firstand second positions. The barge provided by the present invention alsoincludes an arrangement for applying controlled forces between thepontoon section and the hull to effect relative movement between thehull and the pontoon section along the predetermined path in onedirection while preventing all other relative movement between the hulland the pontoon section along the predetermined path throughout allrelative positions of the hull and the pontoon section between the firstand second positions.

Other objects and features of the present invention will appear morefully below from the following detailed Patent O 3,271,964 PatentedSept. 13, 1966 description considered in connection with theaccompanying drawings which illustrate one embodiment of the invention.It is to be expressly understood however, that the description anddrawings are designed for purposes of illustration only and not as adefinition of the limits of the invention, reference for the latterpurpose being had to the appended claims.

In the drawings, in which similar reference characters denote similarelements throughout the several views:

FIG. 1 is a perspective view of a submersible barge constructed inaccordance with the principles of the present invention;

FIG. 2 is a plan view, partially in section, of the submersible bargeshown in FIG. 1;

FIG. 3 is an enlarged isometric view of one of the pontoon supportingstructures incorporated in the submersible barge shown in FIG. 1;

FIG. 4 is a plan view, partially in section, of a portion of thesupporting structure shown in FIG. 3;

FIG. 5 is a view in section taken along the line 5--5 of FIG. 4;

FIG. 6 is a View in section taken along the line 6--6 of FIG. 4;

FIG. 7 is an enlarged view in elevation of a portion of the aft end ofthe submersible barge shown in FIG. 1;

FIG. 8 is an enlarged view in side elevation of the portion of thesubmersible barge shown in FIG. 7;

FIG. 9 is a view in section taken along the line 9-9 of FIG. 7;

FIG. 10 is a view in section taken along the line 1010 of FIG. 9;

FIG. 11 is a side elevational view of a bearing support shown in FIG. 3;

FIG. 12 is an end elevational view of the bearing support shown in FIG.11;

FIG. 13 is a side view in elevation of another bearing support employedin the submersible barge shown in FIG. 1;

FIG. 14 is a plan view of a portion of the submersible barge shown inFIG. 1 illustrating another feature provided by the prwent invention;

FIG. 15 is an elevational view of the structure shown in FIG. 14; and

FIGS. 16, 17, 18, 19, 20 and 21 are diagrammatic representations of thesubmersible barge during different phases of submerging and refloatingoperations according to one method provided by the present invention.

With reference more particularly to FIG. 1 of the drawings, asubmersible barge constructed in accordance with the principles of thepresent invention is disclosed therein comprising a main structure orsection including a hull 10 of substantially rectangular form providedwith a drilling slot 11 extending centrally inwardly from the forwardend of the hull, an open work structure 12 extending upwardly from theupper deck 13 of the hull 10 and a working platform 14 supported by theopen work structure in spaced relation above the hull 10. The open workstructure 12 may comprise a plurality of longitudinally and transverselyspaced vertically disposed column members 15, which may be of tubularconstruction, stabilized by inner-connecting angularly disposed bracemembers 16. The working platform 14 is adapted to support suitableequipment for a submarine operation, such as a drilling derrick 17positioned above the drilling slot 11, and provides suitable space forequipment required in connection with the submarine operations as wellas quarters for members of the operating crew. The depth of the hull 10and the height of the column members 15 determine the maximum depth ofthe submarine operations, the maximum operating depth being less thanthe combined height of the column members and the hull 10 to providewave clearance space beneath the working platform. A submersible bargeconstructed in accordance with the principles of the present inventionand designed for offshore drilling operations includes a hull of a depthof approximately 13 feet and column supporting members extending 48 feetabove the upper deck of the hull and is capable of performing drillingoperations in water depths up to and including approximately 40 feet. Itis to be expressly understood, however, that the principles of thepresent invention may be incorporated in submersible barges havinggreater maximum operating depth by rn'erely increasing the length of thecolumn supporting members with or without an increase in the depth ofthe hull as will be more fully understood from the followingdescription.

The submersible barge also includes a pontoon section comprising a pairof pontoons 1 8 and 19 of elongated rectangular construction arrangedoutboard the main structure. The pontoons 1'8 and 19, and the hull 10,are divided into a plurality of ballast compartments, not shown, andmeans, also not shown, are provided for introducing and removing waterballast from the compartments to control the buoyancy and mass of thepontoon section and the main section. The means for introducing andremoving water ballast from the com-partments may be of any conventionalconstruction and does not constitute a part of the present invention.For example, the various compartments may be connected to valvecontrolled conduits leading to a source of water under pressure, whichmay be supplied by a mechanical pump, for introducing water ballast intothe compartments, and an injector pumping arrangement may be providedfor withdrawing water ballast from the com partments.

In accordance with the principles of the present invention, the pontoonsection is mounted for vertical movement with respect to the hull todifferent positions along a predetermined path including a firstposition in which the center of displacement of the pontoon section isclose to the center of displacement of the hull, a second position inwhich the center of displacement of the pontoon section is above theupper deck of the hull and close to the working platform 14 and tosuecessive positions intermediate the first and second positions. Theforegoing means comprises a plurality of pairs of elongated guidemembers 20, 20 and 21, 21 mounted on both sides of the main structureadjacent the aft end and the fore end of the barge, respectively, andadapted to slidably support pontoon carrying frames 22 and 23,respectively, having connections with the upper decks 24 and 25 of thepontoons 18 and 19, re-

spectively. As shown more clearly in FIG. 2, the pontoons 18 and 19 areprovided at their aft ends with a pontoon earring frame 22 slidablysupported on a pair of guide rails 20, 20, and with a pontoon carryingframe 23 at their force ends slidably supported by pairs of guide rails21, 21.

The present invention also provides novel means for applying controlledforce between the pontoon section and the main structure to move thepontoon section relative to the hull 10, in either direction along thepredetermined path between the first and second positions Whilepreventing relative movement along the predetermined path in theopposite direction, as well as for preventing relative movement ineither direction along the predetermined path at any position along thepath. The above means comprises a pair of double acting hydraulicallyactuated rams 26 and 27 connected between the pon-toons 18 and 19 andthe main structure adjacent the aft end of the barge and a pair ofdouble acting hydraulically actuated rams 28 and 29 connected betweenthe pontoons and the main structure adjacent the fore end of the barge.The lower ends of each pair of hydraulic rams are universally secured tothe upper deck of respective pontoons on opposite sides of a pontooncarrying frame, with their upper ends universally connected to anchoringmeans which are adapted to be fixed at predetermined points along theguide rails associated with respective pontoon carrying frames.

The pontoon carrying frames 22 and 23 may be of identical constructionand, as shown in FIG. 3, include a pair of parallel vertical members 30and 31 spaced from each other a distance corresponding substantially tothe spacing between pairs of guide rails, such as the guide rails 20,20. The upper and lower ends of the vertical members are joined to theends of parallel horizontal members 32 and 33, the vertical andhorizontal members being braced in their plane by means of diagonalbracing members 34 and 35 and vertical bracing members 36. The pontooncarrying frames further include a transverse member 37 extendingoutwardly from the vertical plane of the vertical and horizontal membersand having its inner end joined to the mid point of the lower horizontalmember 33 and its outer end terminated outboard of the mean longitudinalaxis of the pontoon, such as the pontoon 18. The transverse member 37 ispositioned with its longitudinal axis perpendicular to the longitudinalaxis of the horizontal member 33 and to the plane of the vertical andhorizontal members 30, 31, 32 and 33. This perpendicular relationship ofthe member 37 is maintained by means of horizontal bracing members 38and 39 having outer ends joined to a medial point of the transversemember 37 and inner ends connected to the region of the joint betweenthe lower horizontal connecting member 33 and the lower ends of thevertical members 30 and 31, and by means of angularly disposedconnecting members 40 and 41 having their outer ends joined to a medialposed walls of the tubular members. It is to be expressly understood,however, that the pontoon carrying frames may be constructed fromelements having different crosssectional shapes, such as I-shapedmembers, for example.

The pontoon carrying frames are supported by respective pairs of guiderails by means of novel coupling arrangements located in housings 45which may be formed as an integral part of the frames in the region ofthe joints between the ends of the vertical members 30, 31 and thehorizontal members 32, 33. The coupling arrangements may be of similarconstruction as shown in FIGS. 4, 5 and 6. As shown, the housing 4 5 isof substantially U-shaped cross section including parallel elongatedend' portions 46 and 47 having their inner longitudinal edges connectedto opposite longitudinal edges of an elongated side portion 48. Portionsof the vertical and horizontal members of the frame, such as the members30 and 32 are cut away in the region of their joint to provide anopening for receiving the housing 45 which may be weldably secured tothe tubular members. In order to increase the strength of the connectionbetween the housings and the tubular members, a gusset plate 49 mayextend through the tubular member 32 and be notched to encompass theouter periphery of the housing 4-5 and to be weldably secured thereto.The housing 45 also includes elongated partition walls 50 and 51extending longitudinally of the side wall portion 48 outwardly from theinside surface of the side wall portion in spaced relation with the endwall portions 46 and 47, respectively, and terminating in coplanarbearing surfaces 52 and 53 spaced inwardly of the housing with respectto the outer free edges of the end portions 46 and 4-7. The partitionwalls 50 and 51 are of reduced thickness adjacent the side wall portion48 to provide portions 54 and 55, respectively, which projects outwardlyfrom respective partition walls in a direction toward the insidesurfaces 56 and 57 of the end wall portions 46 and 47, respectively, inspaced relation with the inside surfaces 58 and 59 of the side wallportion 48 between corresponding end wall portions and partition walls.The spaces defined by the internal surfaces of the end portions,corresponding partition Walls, and the portion of the side wall betweencorresponding end portions and partition walls are adapted to receivethe inner ends of C-shaped clamping shoes 60 and 61. The clamping shoes60 and 61 may be of identical construction including an intermediateportion 62 presenting an external bearing surface 63, an outer leg 64presenting an internal hearing surface 65 and an inner leg 66 presentingan external bearing surface 67 and an internal bearing surface 68. TheC-shaped shoes 60 and 61 are proportioned to be received by the housing45 with the external surface 63 of the intermediate portion 62 lying incontiguous relation with the inside surfaces 56 and 57 of the end wallportions and with the internal surface 67 and the external surface 68lying in contiguous relation with the internal surfaces 58 and 59 of theend wall portion 48 and the opposed internal surface of the projectingportions 54 and 55, respectively. The clamping shoes 60 and 61 have adepth less than the depth of the housing 45 and are positionedintermediate the top and bottom of the housing by means of lowerretaining members 70 and 71 and upper retaining members 72 and 73. Theretaining members may be of rectangular cross section and are adapted tobe inserted through suitable openings 74 porvided in the end wallportions 46 and 47, across the space between the end wall portions andrespective partition walls 50 and 51 into suitable slots 75 formed inthe partition walls. The lower retaining members 70 and 71 may bepermanently attached to the housing by means of welds 76, while theupper retaining members 72 and 73 are removably retained in the housingby means of studs 77 threadably mounted in the projections 54 and 55 andadapted to engage respective retaining members in the manner shown inFIG. 5.

The guide rails 20 and 21 comprise vertically disposed elongated membersof rectangular cross-section rigidly supported by the main structureoutboard of the side surfaces of the hull 10, the open work structure 12and the working platform 14 with the inside and outside surfaces of theguide rails, on each side of the main structure, lying in correspondingparallel common planes perpendicular to the upper deck 13 of the hull10. Each of the guide rails extend substantially throughout the depth ofthe working platform 14 and the hull and throughout the height of theopen structure 12. As shown in FIGS. 7 and 8, the portions of the guiderails overlying the side walls of the working platform and the hull aresecured to the working platform and the hull in spaced relationtherewith by means of pairs of spaced parallel elongated members 81, 81and 82, 82 welded throughout their length to the inside surface of theguide rails, inwardly of their longitudinal edges, and to the externalsurfaces of the working platform and the hull. The manner in which theportions of the guide rails are attached to the open frame structure 12is illustrated in FIG. 4. As shown, a pair of elongated members 83 and84, extending throughout the length of the column members between theupper deck 13 of the hull 10 and the lower surface of the workingplatform 14, include spaced parallel portions 85 and 86 having theiroutside longitudinal edges weldably secured in perpendicular relation tothe inside surface of the guide rails inwardly of the side edges of theguide rails. The elongated members 83 and 84 also include portions 87and 88 having their outer longitudinal edges joined to the innerlongitudinal edges of respective parallel portions 85 and 86 andinclined away from each other and extended into contact with the sidesof a column member 15 and welded thereto. As seen from FIGS. 1 and 2, acolumn member 15 is positioned at the desired location of each of theguide rails 20 and 21. In order to increase the strength of the guiderail supporting structure, a plurality of vertically spaced horizontallydisposed plates 89 are weldably secured within the space defined by theguide rail, the elongated members 83 and 84 and a portion of the columnmember 15. Also, a plurality of vertically spaced horizontally disposedplates or diaphragms may be similarly secured between the elongatedmembers 81, 81 and 82, 82.

As shown more clearly in FIG. 4, the partition walls 50 and 51 of thehousing are spaced relative to the width of the guide rails, such as aguide rail 20, so that outer marginal areas 90 and 91 of the outsidesurface of the guide rail overlie the bearing surfaces 52 and 53 forbearing contact therewith upon the pontoons being moved inwardly towardthe hull 10. Also, the legs 64 and 66 of the C-shaped shoes 60 and 61are proportioned to space the internal bearing surfaces 65 of the legs64 from respective bearing surfaces 52 and 53 a distance greater thanthe thickness of the guide rail and the C- shaped shoes are positionedrelative to each other with respect to the transverse dimension of theguide rail so that the legs 64 project inwardly beyond the outerlongitudinal edges of the guide rail to position the interior bearingsurfaces 65 in overlying relation with outer marginal areas 93 and 94 ofthe inside surfaces of the guide rail projecting outwardly from thesupporting members 81, 82, and 86. With this arrangement, upon thepontoons moving outwardly with respect to the hull 10, bearing contactis established between the internal bearing surfaces 65 of the leg 64and the marginal areas 93 and 94 on the inside surface of the guiderail.

It is to be expressly understood that each of the housings 45, locatedat the upper and lower ends of the vertical members 30 and 31 of each ofthe pontoon carrying frames includes an attaching arrangement similar tothe structure shown in FIGS. 4, 5 and 6 as described above. Inasmuch asgreater forces may exist at the points of connection between the guiderails and the lower ends of the pontoon carrying frames, the attachingarrangements in the housings at the lower ends of the members 30 and 31may be of increased depth to provide additional bearing area between thecontacting surfaces. Otherwise, the bearing attachments may be ofsimilar construction.

The attaching arrangements of the housings 45 of each of the pontooncarrying frames are designed so that the pontoons may be easily attachedto and removed from the main structure. When it is desired to detach thepontoons, the upper retaining members 72 and 73 are removed from thehousing by first unthreading the retaining studs 77. The C-shaped shoes60 and 61 may then be removed upon upward movement relative to thehousing, preferably with the pontoon stationary with respect to the mainstructure and with the bearing surfaces 52 and 53 in contact with themarginal area and 91 of the guide rail. Lifting lugs, not shown, may beprovided on the upper ends of the shoes for use in their removal. Whenthe retaining shoes are removed from the housings of the pontooncarrying frames of a pontoon, the pontoon may be floated away from themain structure. The pontoons may be attached to the main structure byreversing the above procedure.

It should be noted that the arrangement provided by the presentinvention for attaching the pontoon carrying frames to the guide railsallows limited relative inboard and outboard movement between thepontoons and the main structure. Thus, when an inwardly moving force isapplied to pontoons, the pontoons move inwardly toward the mainstructure to establish bearing contact between the marginal areas 90 and91 on the outer surface of the guide rails and the bearing surfaces 52and 53 presented by the housing, and upon an outwardly moving forcebeing applied to the pontoons, the

pontoons move outwardly a predetermined distance to establish bearingcontact between the marginal areas 93 and 94 on the inside surface ofthe guide rail and the internal bearing surfaces 65 of the legs 64. Thisarrangement eliminates problems that would be present in an arrangementin which bearing contact is simultaneously maintained on both sides ofthe guide rails. If desired, the bearing surfaces of the housing 45 andthe retaining shoes 60 and 61 may comprise inserts of suitable hearingmetal to provide long life as well as an arrangement for establishingand maintaining the required clearances between the bearing surfaces bymeans of shims.

As mentioned above, a pair of double acting hydraulic rams 26 and 27 areconnected between the pontoons 18 and 19 and the main structure adjacentthe aft end of the barge, and a pair of double acting hydraulic rams 28and 29 are connected between the pontoons 18 and 19 and the mainstructure adjacent the fore end of the barge. Also, the hydraulic rams26 and 27 are located on opposite sides of the pontoon carrying frames22, while the hydraulic rams 28 and 29 are located on the opposite sidesof the pontoon carrying frames 23. The hydraulic rams may be of similarconstruction and each may be connected between the main structure andrespective pontoons as shown in FIGS. 7, 8, 9 and 10.

As shown, the hydraulic ram 26 includes a cylinder portion 100 and apiston portion 101. The piston portion is provided with a piston, notshown, carried at its lower end and slidably mounted in the cylinderportion and adapted to be subject to fluid pressure on its oppositesides to positively move the piston portion 101 in either direction withrespect to the cylinder portion 100. Suitable hydraulic connections, notshown, are provided for introducing fluid pressure into the hydraulicram. The barge is provided with suitable sources of fluid pressure and acontrol circuit, not shown, for selectively actuating the hydraulic ramsin a manner described fully below. The lower end of the cylinder portionis universally connected to the upper deck 24 of the pontoon 18 by meansof a universal joint 102 provided with a parallel link connection 103 toprevent rotation of the ram. The universal joint is located slightlyoutboard of the mean longitudinal axis of the pontoon deck in a planeperpendicular to the side surface 80 of the hull and passing through thecentral longitudinal axis of one of the guide rails 20.

The upper end of the piston portion 101 is detacha-bly secured to theguide rail 20 at dilferent predetermined vertically spaced points alongthe guide rail by means of a connecting device 104. As shown moreparticularly in FIGS. 9 and 10, the connecting device 104 comprises a.housing 105 having a vertically disposed body portion 106 and ahorizontally disposed body portion 107. The body portion 106 is providedwith a substantially wide groove 108 in its outer face extendinglongitudinally throughout the depth of the body portion. The groove 107extends inwardly from the outer face and terminates in communicationwith a pair of diametrically opposed transversely disposedlongitudinally extending slots 109 and 110. The groove 108 is ofsufiicient width to receive the spaced parallel supporting members ofthe guide rail, such as the supporting members 87 and 88, and thetransversely disposed grooves 109 and 110 are proportioned to receivethe longitudinal edges of the guide rail which project outwardly beyondthe supporting members 87 and 88 to slidably support the connectingdevice 104 on the guide rail. The body portion 107 is provided with ahorizontally disposed passageway 111 of rectangular crosssection whichslidably receives a rectangular retaining member 112. One end of theretaining member 112 is connected to actuating rod 113 of a hydrauliccylinder 114 operable upon energization to reciprocate the retainingmember 112 between a first position shown in full lines in FIG. 9 and asecond position shown in broken lines. A rectangular opening 115 isformed in the guide rail 20 between the supporting members 87 and 88 toprovide a passageway through the guide rail for receiving the retainingmember upon movement of the retaining member to and from the secondposition. The body portion 107 includes a downwardly depending housing116 designed to receive a ball connector 117 secured to the upper end ofthe piston portion 101 and universally join the hydraulic ram to theconnecting device 104.

In addition to the openings 115, each guide rail is provided with aplurality of similar openings 118, 119 and 120 vertically spaced abovethe opening 115, as shown in FIG. 8. Each of the openings 118, 119 and120, like the opening 115, is adapted to receive the retaining member112, when moved into alignment therewith, to rigidly anchor the upperend of the piston portion 101 to the guide rail at the points of theopenings. The lowermost openings 115, establishing the first anchorpoint, are located a predetermined distance above the deck of the hullso that, upon the upper ends of the piston portions 101 being anchoredto respective guide rails at that point, the center of displacement ofthe pontoon section will be close to the center of displacement of thehull with the hydraulic rams in a substantially fully contractedcondition. This relationship is shown in full lines in FIG. 7. The nexthigher openings 118, which establish the second anchor point, arepositioned above the first anchor point a distance substantiallycorresponding to the eifective stroke of the hydraulic rams, while thenext higher openings 119 at the third anchor point are spaced a similardistance above the openings 118. The openings 120 are located at the topof the guide rails and may be spaced a distance equal to or less thanthe effective stroke of the hydraulic rams. It is to be expresslyunderstood that any number of openings or anchor points may be providedalong the guide rails, the number and the spacing therebetweenordinarily being determined by the effective stroke of the hydraulicrams and the operating depth of the barge. In FIG. 7 the ram 26 shown inbroken outline is illustrated in extended condition joined to the guiderail at the second anchor point.

In accordance with another feature of the present invention the pontooncarrying frames 23 at the fore end of the barge are attached to theupper decks 24 and 25 of the pontoons 18 and 19 by means of transverselyspaced bearings and 131 rigidly secured to the upper decks of thepontoons, while the pontoon carrying frames 22 at the aft end of thebarge are attached to the pontoons by means of transversely spacedbearings 132 and 133 secured to the upper decks of the pontoons forsliding movement longitudinally of the pontoons. As shown in FIG. 3, thetransverse member 37 of the pontoon carrying frames 22 includes aportion 134 extending outwardly beyond the region of connection of thebracing members 38, 39, 40 and 41, and a portion 135 inboard of theconnecting region. The portions 134 and 135 are rotatably supported bybearings 132 and 133, respectively, attached by a sliding carriagestructure 136 to the upper deck 24 of the pontoons. Retaining collars137 may be positioned on the portions 134 and 135 on opposite sides ofthe bearings.

The bearings 132 and 133 may be constructed as shown in FIGS. 11 and 12.The bearing 132 may include a movable upper housing 140 and a relativelystationary lower housing 141, each of the housings being provided withconnecting flanges 142. The lower housing 141 is supported by a columnmember 143 including a flat rectangularly shaped bearing plate 144 atits lower end having side portions 145 extending outwardly beyond thesupport 143. The bearing plate 144 is adapted to slidably contact abearing surface 146 presented by a bearing member 147 rigidly secured,by any suitable means, to the upper deck 24 of the pontoon 18.Stationary retaining members 148 are rigidly secured to the uppersurface of the bearing member 147 on both sides of the bearing plate 144in sliding contact with the upper and edge surfaces of the bearing plateto prevent relative vertical and transverse movement between the hearing132 and the pontoon 118 but to allow limited movement of the bearingmember 132 longitudinally of the pontoon. The retaining members 148 donot simultaneously contact opposite sides of the bearing plate and thecolumn member and allow limited transverse movement therebetween in amanner corresponding to operation of the sliding connection between thepontoon carrying frames and the guide rails.

The bearings 130 and 131 rotatably supporting the pontoon carryingframes 23 at the fore end of the barge are positively secured to theupper decks of the pontoons by any suitable construction, such as thearrangement shown in FIG. 13. In this figure, a bearing 130 is shownsupported by a member 150 positively anchored to the upper deck 24 ofthe pontoon 18 by means of an anchor plate 151. In other respects thebearings 130 and 131 may be constructed similarly to the bearings 132and 133 to include a removable upper housing 152 and a stationary lowerhousing 153 having innerconnecting flanges 154.

During operation of the barge, due to weather conditions or for otherreasons, abnormal forces may be present causing the pontoons to moveinwardly or outwardly with respect to the main structure and transmitheavy stresses to the pontoon supporting structures. In order toincrease the stability of the barge and prevent application of abnormalforces on the pontoon supporting structures, the present inventionprovides lateral movement restraining means connected between the hulland the pontoons which may or may not but preferably are utilized withresilient fenders supported on the sides of the hull spatially along itslength for contact with the inboard sides of the pontoons. The lateralmovement restraining means are designed to limit inboard and outboardmovement of the pontoons relative to the main structure to a degree lessthan the total relative inboard and outboard movement between the mainstructure and the pontoons permitted by the connections between thepontoon carrying frames and the guide rails and between the pontooncarrying frames and the pontoons. As shown in FIG. 2, lateral movementrestraining means 160 and 161 are positioned adjacent the fore and aftends of the barge, respectively, between the opposing side surfaces ofthe pontoon 18 and the hull 10, and lateral movement restraining means162 and 163 are positioned at the fore and aft ends of the barge,respectively, between the opposing side surfaces of the pontoon 19 andthe hull The lateral movement restraining means may be of similarconstruction and a detailed description of the lateral movementrestraining means 160 will be suflicient to fully describe this featureof the invention. As shown more particularly in FIGS. 14 and 15, thelateral movement restraining means 160 includes an elongated anglemember 164 secured to the side surface 80 of the hull 10 and anelongated angle member 165 secured to the adjacent side surface 166 ofthe pontoon 18. The elongated angle member 164 includes a firstvertically disposed portion 167 having one longitudinal edge secured tothe side surface 80 of the hull in substantially perpendicularrelationship with the side surface. The other longitudinal edge of theflange portion 167 is joined to a longitudinal edge of anothervertically disposed flange portion 168 extending toward the fore end ofthe hull parallel to the surface 80. The elongated angle member 165 alsoincludes a vertically positioned flange portion 169 secured inperpendicular relation to the side surface 166 of the pontoon 18, andhaving its outer longitudinal edge joined to a longitudinal edge of avertically disposed flange portion 170 extending at right angles fromthe flange portion 169 in a direction toward the flange portion 167 ofthe angle member 164. The flange portions 167 and 169 extend outwardlyfrom the side walls 80 and 166, respectively, beyond the parallel flangeportions 168, 170 of the other angle member, and the parallel flangeportions 10 168 and 170 extend a sufiicient distance toward the otherflange portion of the opposite angle member to establish an overlappingrelationship as shown in the drawing. In FIGS. 14 and 15, the hull 10and the pontoon 18 are shown in an intermediate position of the maximuminward and outward movement allowed by the restraining means 160. Thus,inward movement of the pontoon relative to the hull is limited uponcontact of the flange portion 170 with the side of the hull and of theflange portion 168 with the side 166 of the pontoon, While outwardmovement is limited upon contact between the flange portions 168 and170, the maximum inward and outward movement being limited to the spacebetween the flange portions 168 or 170 and the surfaces 166 and 80,respectively, plus the space between the flange portions, as shown inFIG. 14. According to the present invention, the maximum inward andoutward positions of the pontoons relative to the hull 10' is limited bythe lateral movement restraining means to positions less than themaximum inward and outward positions of the pontoons relative to thehull as determined by the attaching structure between the pontoonsupporting frames and the guide rails and between pontoon supportingframes and the pontoons. With this arrangement the lateral movementrcstraining means will absorb forces tending to move the pontoonsrelative to the hull and prevent application of heavy moments about theattaching structure for the pontoon supporting frames. As mentionedabove, the lateral movement restraining means may be employed withresilient fenders spatially positioned along the side 80 of the hull andextending substantially throughout the depth of the hull. These fendershave a lateral dimension at least equal to the minimum space between theside surfaces of the pontoons and the hull is determined by the lateralmovement restraining means. Thus, forces moving the hull and thepontoons in a direction toward each other are absorbed by the resilientfenders, and the resilient fenders function to add stability to thebarge when the pontoons are at their innermost position with respect tothe hull. It should be noted from FIG. 15 that the angle members 164 andextend a substantial distance throughout the depth of the pontoonsection 18 and the hull to provide a relatively large area of contactbetween the angle members and also to provide a lateral movementrestraining function even when the center of displacement of thepontoons and the hull do not lie in a common horizontal plane whichfrequently occurs during normal operation of the barge as will appearbelow. It is to be understood that the lateral movement restrainingmeans may be provided in other forms and this feature of the inventionis not limited to the use of spaced right angle members as shown anddescribed above.

Operation of a submersible barge constructed in accordance with theprinciples of the present invention will be more fully understood fromreference to FIGS. 16 through 21 of the drawings. In FIG. 16, the bargeis shown in towing position in which the ballast in the compartments ofthe hull 10 and the pontoons 18 and 19 is controlled to buoyantlysupport the barge. In the towing position, the center of displacement ofthe pon toons substantially corresponds to the center of displacement ofthe hull, and the hydraulic rams are in a substantially fully contractedposition with the upper end of the ram pistons being secured torespective guide rails at the first or lowermost anchor point. Thecylinder chambers of the hydraulic rams on opposite sides of the rampistons are filled with substantially incompressible fluid to preventrelative movement between the piston portion 101 and the cylinderportion 100 and provide rigid connections between the pontoons and themain structure. During towing operations, the pontoons are ordinarilysecurely tied to the hull by means of wire rope, for example, to preventrelative lateral movement. The lateral movement restraining means 160,161, 162 and 163 are therefore positioned with the flange portions 168and in contact with the pontoon side wall 166 and the hull side wall 80,respectively, and function to provide a stable, unitized structure. Theprovision of resilient fenders as discussed above will further stabilizethe barge. Upon the barge reaching location for submarine operations,the hydraulic rams are disconnected from their respective guide railsand are energized with fluid pressure to move the rams into rigidextended positions with their supporting devices 104 in alignment withthe next higher opening 118 in the guide rails. The hydraulic cylinders114 are then actuated to connect the hydraulic rams to the second anchorpoint. This position of the barge shown in FIG. 17. The rams need not bemoved in any specific order; however, in some cases such as whenoperating in heavy seas, it is advantageous to move the rams one at atime, or to move the rams of each pair successively, to maintain rigidconnections between the pontoon section and the main structure.

With the barge in the position shown in FIG. 17 the hull may besubmerged to the underlying land bottom by varying the mass-buoyanceratio of one of the sections, i.e., the main section or the pontoonsection, to thus decrease the buoyant condition of the barge, and byapplying controlled force between the sections, by means of thehydraulic rams, to controllably cause the bull to move in a directiontoward the underlying land bottom while maintaining the pontoon sectionwith sufiicient freeboard to stabilize the barge. The buoyant conditionof the barge may be decreased to effect submergence of the hull byvarying the mass-buoyance ratio of either of the sections, and the hullsubmergence may be accomplished with both of the sections buoyant, orwith either of the sections non-buoyant and the other section buoyant.Also, as will appear more fully below, during one portion of the hull submergence, one section may be buoyant and the other section non-buoyant,while during another portion of the submergence the one section may benonbuoyant and the other section buoyant.

The term mass-buoyance ratio, as used throughout this description and inthe appended claims, defines the ratio of the mass of a body, such aseither of the sections, and its buoyance which determines whether or notthe body is buoyant or non-buoyant. Thus, either of the sections may berendered buoyant or non-buoyant by decreasing or increasing the mass ofthe sections or by increasing or decreasing the buoyance of thesections, respectively.

According to one method for submerging the hull, the buoyant conditionof the barge is decreased by varying the mass-buoyance ratio of the mainsection upon adding suflicient ballast to the compartments of the hullto render the main section non-buoyant, or preferably slightlynon-buoyant.

The term slightly non-buoyant as used throughout this description and inthe appended claims, defines a condition in which suflicient ballast hasbeen added to the compartments of the hull to reduce the resultant ofthe buoyance of the hull and the mass of the main section to a degreejust insufiicient to support the total weight of the main section.

When the main section is rendered non-buoyant, the rams may becontracted under control of hydraulic circuit means associated with therams to apply controlled force between the sections and controllablyeffect downward movement of the hull relative to the pontoon section ina direction toward the underlying land bottom, eventually submerging thehull to the land bottom. During this performance, the pontoon section,being buoyant, is maintained with adequate freeboard to stabilize thebarge. FIG. 18 illustrates an intermediate position of the hullsubmergence, while FIG. 19 shows the hull submerged to the load bottom.In both figures, the pontoon section, i.e., pontoons 18 and 19, areshown with adequate freeboard to stabilize the barge It is preferable,as men tioned above, to only add a quantity of ballast to thecompartment of the hull to render the main section slight- 1ynon-buoyant. Under these conditions the major proportion of the totalWeight of the main structure is supported by the buoyance of the hulland forces of relatively small magnitude exist tending to submerge thehull. This makes it possible to submerge the hull according topredetermined plans concerning the attitude of the hull duringsubmergence as will be discussed below, and greatly enhance the safetyof the operation, since the magni tude of the controlled forces betweenthe sections are proportionately decreased. This feature is especiallyadvantageous when the operation takes place in heavy seas. Under idealconditions, that is in perfectly calm water, the controlled forcebetween the sections may be negligible providing contraction of the ramsis initiated at a time when the main section changes from a buoyantcondition to a non-buoyant condition and the rams are contracted at arate corresponding to the natural submerging of the hull due to thenon-buoyant condition of the main section. However, due to the mass ofthe sections of the barge and the magnitude of the forces involved, andsince swells are frequently present producing temporary displacement ofthe resultant forces of the liquid ballast, or for other reasons,controlled forces of appreciable magnitude may be applied between thesections, and it frequently occurs that controlled forces of differentmagnitude are applied at difierent points between the sections. Also, itmay be desirable in some cases to control the hydraulic rams in such amanner as to apply controlled forces of predetermined magnitude betweenthe sections to maintain the hull at a desired attitude during itssubmergence, as well as to control its rate of submergence. For example,it may be desirable to submerge one end of the hull beneath the watersurface ahead of the other end, to maintain the hull at such an attitudethroughout its submergence causing one end of the hull to be submergedto the land bottom ahead of the other end, or to change the attitude ofthe hull during its submergence and cause the hull to be submerged tothe land bottom in a different manner. While the distribution of ballastin the compartments of the hull influence the attitude of the hull, theprovision of hydraulic rams operable to apply controlled forces betweenthe sections provides an arrangement for more accurately establishingand maintaining a desired hull attitude throughout the submergence aswell as for compensating for extraneous influences which adverselyaifect the function of the ballast in maintaining a desired hullattitude.

According to another method provided by the present invention, thebuoyant condition of the barge may be decreased by varying themass-buoyance ratio of the pontoon section and the hull may becontrollably submerged upon opertion of the hydraulic rams with the mainstructure in a buoyant condition. In particular, with the sections ofthe barge in the positions shown in FIG. 17, the rams may behydraulically contracted, in a controlled manner, to move the pontoonsection relative to the hull 10 along the predetermined path in adirection toward the second position to decrease the buoyance of thepontoons 18 and 19. When the buoyance of the pontoon section isdecreased to a degree suflicient to render the barge nonbuoyant, thehull will submerge to the underlying land bottom with the barge beingstabilized by the pontoon section maintained with adequate freeboard forthis purpose. By continuously contracting the hydraulic rams at a rateto apply proper controlled force between the sections, the hull may besubmerged to the underlying land bottom in any desired attitude. Themain section is in a buoyant condition during this method of hullsubmergence, and the pontoon section may be buoyant or non-buoyant. Forreasons mentioned above, it is preferable to add sufiicient ballast tothe compartments of the hull 10 to render the main section slightlybuoyant. Of course, in the case of a non-buoyant pontoon section, thebarge should be rendered slightly buoyant. The terms slightly buoyant asused throughout this description and in the appended claims defines acondition in which the resultant of the buoyance of a body, such as themain sec tion or the barge, and the mass of the body is just sufii-'cient to support the total weight of the body. It is to be expresslyunderstood the present invention is not limited to methods in which themain structure is rendered slightly non-buoyant, or the main structureor the barge is rendered slightly buoyant, prior to submergence of thehull, but that these conditions comprise the preferred mode ofoperation.

The above described methods of submerging the hull with the main sectionin a buoyant or a non-buoyant condition may be followed during a singlesubmergence of the hull. For example, at the beginning of the submergence operation with the barge in the condition shown in FIG. 17,contraction of the hydraulic rams may be initiated at a time beforesufficient ballast has been added to the compartments of the hull torender the main section non-buoyant. Thus, initial submergence of thehull may take place with the main section buoyant, and after suffi cientballast is added to the hull to render the main section non-buoyant, thesubmergence of the hull may be completed with the main sectionnon-buoyant. It is also possible, during an intermediate phase of thehull submergence, as shown in FIG. 18, to change the main section from abuoyant condition to a non-buoyant condition, and vice versa, during thenormal course of the submergence in accordance with a predetermined planof submergence or in order to compensate for changing conditions. Forexample, it may be desirable in some cases to submerge the hull duringthe first half of the submergence with the main section in a buoyantcondition and during the second half of the submergence with the mainsection in a non-buoyant condition. With this procedure, upon structuralfailure, the hull will move to the water surface or to the underlyingland bottom whichever is at the least displacement from the hull at thetime of the structural failure.

The relative movement between the pontoon section and the hull asdetermined by the hydraulic rams is established by controllablyexhausting substantially incompressible fluid from the cylinder chambersof the hydraulic rams beneath the ram pistons while at the same timeadding fluid to the cylinder chambers above the ram pistons to maintainthe latter chambers filled with fluid and hence prevent upward movementof the piston portion 101 rela tive to the cylinder piston 100. Thehydraulic rams thus provide rigid connections between the sections ofthe barge, which connections are extensible or contractible whilemaintaining the connections rigid. The main structure therefore may bemoved downwardly with respect to the pontoon section at a ratedetermined by the rate fluid is exhausted from the cylinder chambersbeneath the ram pistons, until the hydraulic rams reach their fullycontracted condition or until the hull is submerged to the underlyingland bottom 180, shown in FIG. 19.

When a non-buoyant structure is allowed to sink, or when a buoyantstructure is forceably submerged, such as the main structure, it is notpossible to predetermine the attitude of the structure during itssubmergence. This is especially so when liquid ballast is employed tocontrol the mass of the structure. Therefore, in accordance with theprinciples of the present invention, fluid is selectively exhausted fromthe hydraulic rams in such a manner as to maintain the hull in apredetermined attitude during its submergence. Also since upwardmovement of the piston portions 101 relative to the cylinder portion 100is prevented throughout the submergence of the hull by maintaining thecylinder chambers on the upper side of the ram pistons at all timesfilled with fluid, rigid connections are continuously maintained betweenthe pontoon section and the .main structure. This feature aids inmaintaining stability of the barge during submerging and refloatingoperations when subject to high winds or swells. Thus, according to thepresent invention, controlled forces are supplied between the pontoonsection and the main section to move the hull relative to the pontoonsection in one direction along the predetermined path while preventingrelative movement along the predetermined path between the pontoonsection and the hull in the other direction.

When the hull is submerged to the underlying land bottom, additionalballast may be added to the compartments of the hull to render the mainsection non-buoyant to a substantial degree and cause the hull to restmore firmly on the land bottom. Ordinarily the relationship between themass of the main section and the buoyance of the hull is proportioned toprevent the hull from sinking into the land bottom which generally doesnot present a solid supporting surface.

After the hull is submerged to the land bottom and its mass-buoyanceratio established in accordance with existing conditions, submergence ofthe pontoon section may be initiated. This is accomplished bycontrollably extending the hydraulic rams to move the pontoons 18 and 19from their position shown in FIG. 19 to the position shown in FIG. 20.This may be accomplished with the pontoon section buoyant, slightlybuoyant, non-buoyant or slightly non-buoyant. Ballast may be added tothe compartments of the pontoons 18 and 19 to establish the desiredbuoyant or non-buoyant condition of the pontoon section. Also, byadjusting the ballast and by establishing controlled force between thepontoon section and the main section, by means of the hydraulic rams,the pontoon section may be maintained in any desired attitude duringsubmergence. Upon submergence of the pontoon section to the land bottom,additional ballast may be added to the compartments of the pontoons torender the pontoon section substantially non-buoyant. Thereafter, thehydraulic rams may be disconnected from their respective guide rails andhydraulically moved to their contracted position and connected to theirrespective guide rails at the lowermost or first anchor point, as shownin FIG. 21. The hydraulic rams may then be operated to apply a downwardforce onto the pontoons and push the pontoons a greater distancedownwardly than the hull to further stabilize the barge and preventundercurrents from washing away the land bottom beneath the hull.

When the submarine operation is complete and it is desired to refloatthe barge, the hydraulic rams are disconnected from the first anchorpoints of respective guide rails and are hydraulically extended andconnected to the second anchor point. Ballast in the compartments of thepontoons may then be adjusted if necessary to render the pontoon sectionbuoyant, slightly buoyant, non-buoyant or slightly non-buoyant.T-hereupon the hydraulic rams may be contracted to apply controlledforce between the pontoon section and the main section and move thepontoon section to the position shown in FIG. 19. If substantial suctioneffect exists between the bottom surfaces of the pontoons and the landbottom, it may be relieved by removing ballast from one end only of thepontoons and by hydraulically contracting the hydraulic rams attachedadjacent to the same ends of the pontoons. By this action the lowersurfaces of the pontoons are moved away from the land bottomprogressively from one end to the other to effect a gradual breaking ofthe suction action between the land bottom and the lower surface-of thepontoons without requiring application of forces of substantialmagnitude. This method of relieving the suction effect between thepontoons and the land bottom is made possible by the structure providedby the present invention for connecting the hydraulic rams between thepontoons and the main structure and for attaching the pontoon carryingframes to the upper decks of the pontoons. As described above, the upperand lower ends of hydraulic rams are universally connected to the mainstructure and to the upper decks of the pontoons, respectively, whilethe pontoon carrying frames are attached to the upper decks of thepontoons by means of spaced bearings, the axis of rotation beingperpendicular to the longitudinal axis of the pontoons. Also, thebearings adjacent one end of the pontoons are rigidly attached to thepontoons while the bearings adjacent the other ends of the pontoons aresupported by a carriage slidably mounted longitudinally of the pontoons.With this structure, upon upward movement of one end only of thepontoons the hydraulic rams, through their universal connections, carrythe developed component forces extending longitudinally of the pontoons,and longitudinal stresses are not developed at the slidable jointsbetween the pontoon carrying frames and the guide rails due to therotatable connection between the pontoon supporting frames and thepontoons and due to the allowable longitudinal movement provided 'by theslidable carriage supporting the bearings adjacent one end of thepontoons. Preferably the ends of the pontoons adjacent the pontooncarrying frames supported by the slidable carriages should be liftedfirst in order to prevent concurrent longitudinal movement of thepontoons relative to the land bottom. After the pontoons are relievedfrom the land bottom, they may be refioated in any desired attitude,preferably on even keel.

After the pontoon section is moved to the surface of the water andprovided with sufficient freeboard to stabilize the barge, the buoyancyof the pontoon section is established in accordance with the methodemployed to refioat the hull, that is, for example, if the hull is to berefloated with the main structure non-buoyant, the pontoon section mustbe sufficiently buoyant to support the weight of the main sectionunsupported by the buoyance of the hull. The hull may be refloated in abuoyant or a non-buoyant condition, and its condition may change frombuoyant to non-buoyant, and vice versa, during the refloating operationeither according to a pre-arranged plan of procedure or because ofcircumstances arising during the refloating operation, by varying theballast in the compartments of the hull. Refioating of the hull iseffected by the application of controlled forces between the mainsection and the pontoon section, upon extension of the hydraulic rams.As in the case of submerging the hull, the attitude of the hull duringreiloating may be established and changed by the controlled forces andby ballast distribution, and the hull may be refioated at any desiredattitude. After the ballast in the hull is established, the suctionbetween the hull and the land bottom may be removed by any conventionalmethod such as by introducing streams of Water beneath the bottomsurface of the hull and the land bottom at spaced points throughout thearea of the hull bottom. T he hydraulic rams are then controllablyextended to refloat the hull. The rams vmay then be moved to theirposition shown in FIG. 16, the pontoon section secured to the mainsection and the proper ballast maintained in the compartments toestablish floating buoyancy of the barge. The barge may then be floatedto a new location.

The novel submersible barge structure provided by the present inventionallows beginning of movement of the barge from an old location to a newlocation prior to complete refloating of the hull. Due to the provisionof the hydraulic rams the barge may be towed away from its old locationat a time after the hull is moved upwardly from the land bottom andbefore the hull is refioated. This feature of allowing movement of thebarge with the hull in a partly submerged condition provides a materialsaving in time and in some cases may permit moving from one location toanother without complete refioating of the hull.

FIGS. 16 through 21 illustrate various relative positions of the hulland pontoons during submergence of the barge to land bottom below adepth of water less than the effective stroke of the hydraulic rams plusthe draft of the hull, the depth of water being substantially less thanthe maximum operating depth of the barge. When it is desired to submergethe barge to land bottom below a depth of Water greater than theeifective stroke of the hydraulic rams plus the draft of the hull, suchas a depth approaching or corresponding to the maximum operating depth,the submergence is accomplished by following the sequence of stepsdiscussed above with the pontoon section, the hull and the hydraulicrams sequentially occupying the position shown in FIGS. l6, l7 and 18until the hull is submerged below the surface of the Water a distancedetermined by the effective strokes of the hydraulic rams. This positionis illustrated in FIG. 19, but of course the hull section is notsubmerged to the underlying land bottom since a greater depth of thewater is present. In order to further sub-merge the hull to the landbottom, the hydraulic rams of each pair of hydraulic rams 26, 27, 28 and29 attached to each of the pontoons are unloaded, hydraulicallyextended, connected to respective guide rails at the next higher opening119 comprising the third anchor point, and then reloaded. Duringrelocation of the hydraulic rams to the third anchor point, the weightof the main structure not supported by the buoyance of the hull as inthe case of submergence of the hull in non-buoyant condition, or theWeight of the pontoons supported by the hull in a buoyant condition, iscarried by the loaded rams which will be subsequently relocated, orwhich have been previously relocated, to the third anchor point. Thusthe rams may be successively relocated, or one ram of each pair of ramsor one ram of groups of rams connected to the same pontoon, may berelocated at the same time. In any event, it is preferable to design thehydraulic rams to individually carry the load ordinarily supported by apair of rams. After all the hydraulic rams are extended and relocated tothe third anchor point, they may be controllably contracted to furthersubmerge the hull. It is to be expressly understood that should thedepth of water be such that relocation of the hydraulic rams to thethird anchor point of the guide rails be insuflicient to allowsubmergence of the hull 10 to the underlying land bottom, the hydraulicrams may be relocated to the fourth anchor points, represented by theopenings 120, and thus allow further submergence of the hull to theunderlying land bottom below a depth of water corresponding to themaximum operating depth of the barge as determined by the combinedheight of the open framework 12 and the depth of the hull.

After the hull It is submerged to the underlying land bottom andadditional ballast added to increase its nonbuoyancy, the pontoonsection may be submerged by following the same procedure by which thehydraulic rams are progressively relocated from the highest to thelowest anchor points. Upon complete submergence of the pontoon section,the hydraulic rams may be contracted and relocated at the first anchorpoints, i.e., openings 115, and thereafter hydraulically operated toapply a downward force onto the pontoons. The barge may be refloated byreversing the foregoing procedural steps.

By utilizing pairs of hydraulic rams having different strokes or bystaggering the openings in the pairs of guide rails for each pair ofhydraulic rams, an arrangement may be provided for continuouslysubmerging or refioating the hull throughout the maximum operating depthof the barge. In such an arrangement the rams would be designed andlocated to carry the load ordinarily carried by a pair of rams, and aram of each pair may be unloaded, contracted or extended as the case maybe, to the next higher or lower anchor point, while the other ram of thepair functions to apply controlled force between the main section andpontoon section to effect submergence or refloating of the barge. Thisarrangement permits a material saving in time especially when operatingin Water of a depth several times the effective stroke of the rams,while retaining the structural advantages of relatively short rams.

The provision of a plurality of individually controllable hydraulic ramsconnected between the pontoon section and the main section, with atleast one hydraulic ram being located at the fore end and at the aft endof each of the pontoons, allows submergence of the hull and of thepontoons at any desired attitude, such as an attitude in which thehorizontal axis of the sections is horizontal or inclined with the foreends up and the aft ends down and vice versa. The provision of universalconnections between the ends of the hydraulic rams and the sections andof rotatable connections between the pontoon supporting frames and eachpontoon, one of which is longitudinally slidable relative to thepontoon, allows either of the sections to be submerged with itslongitudinal axis inclined, that is at uneven keel, while the othersection may be maintained at even keel or at a non-level attitude ifdesired. Also, the provision of a plurality of hydraulic rams at thefore end and at the aft end of each of the pontoons allows controlledsubmergence and refloating of the hull and the pontoon sectionthroughout a depth of water materially greater than the effectiveoperating stroke of the hydraulic rams and makes it possible to utilizethe advantageous principle of rigid connections between the pontoonsection and the main section in submarine operations of the order of 40feet or more, for example. Furthermore the feature of providinghydraulic rams that may be anchored at different vertically spacedpoints along their respective guide rails allows the hydraulic rams tobe moved into a substantially contracted condition, and thus protect thecontracting surfaces of the cylinder portion and piston portion of thehydraulic rams, when the barge is in submerged state for an extendedperiod of time during a drilling operation, or when the barge is infloating condition during its movement from one location to another. Theuse of hydraulic rams, connected between the pontoon section and themain section, provides means for determining the mass-buoyance ratio ofthe main section and the pontoon section not only during submerging andrefioating operations but also during a submarine operation, such as adrilling operation. Dead weight of the barge, such as water, mud, pipeand other material required for a drilling operation, for example, arepermanently removed from the barge as the drilling operation proceeds.Since such materials are of considerable mass, a material reduction inthe dead weight of the barge occurs during the drilling operation. Inorder to maintain the required stability of the submerged barge, themass-buoyance ratio of the main section, in particular, and of thepontoon section, must be adjusted in accordance with changes in the deadweight of the barge at different points with respect to the center ofgravity of the barge. Variations of the forces on the hydraulic rams notonly indicate the necessity to adjust the ballast in the compartments ofthe hull and of the pontoon section but constitute a measure of ballastchanges that may be required.

There is thus provided by the present invention a novel submersiblebarge of the type including a main section and a stabilizing pontoonsection capable of operation in relatively deep water of the order of 40feet or more, for example, as well as novel methods of operating thesame. It is to be expressly understood that various changes andsubstitutions may be made in the specific structure disclosed anddescribed above without departing from the spirit of the invention aswell understood by those skilled in the art. For example, the barge maycomprise a main structure including a hull and a platform of triangularshape and a pontoon section comprising a plurality of rectangularpontoons each positioned outboard the main section adjacent the sides ofthe triangular structure, or the main section may be of cylindricalshape including a cylindrical hull and platform joined by open workstructure with the pontoon section comprising an annular member, ofcontinuous or discontinuous construction, positioned about thecylindrical main section. Also, if desired, the barge may include apermanently nonbuoyant pontoon section which may be constructed ofmasonry, such as concrete. Reference therefore, will be had to theappended claims for a definition of the limits of the invention.

What is claimed is:

1. Method of operating a submersible barge to effect submergence thereofto the underlying land bottom of a body of water,

the barge being of the type having a main section including a floatablehull connected to an upstanding open structure supporting a platformspaced above the hull and a pair of pontoon sections located outboard ofthe main section on opposite sides thereof with the main section and thepontoon sections being mounted for relative individual movement inupward and downward directions to different positions alongpredetermined paths including a first position in which the center ofdisplacement of the pontoon sections is at substantially the same levelas the center of displacement of the hull, a second position in whichthe center of displacement of the pontoon sections is displaced amaximum distance above the level of the center of displacement of thehull and successive positions from the center of displacementintermediate the first and second positions,

the method comprising the steps of floating the barge on the body ofwater by the buoyance of the pontoon sections with the hull and thepontoon sections in the first position and each having ftreeboard,

applying a force of controlled variable magnitude between and onto themain section and the pontoon sections and by said force moving the hullat selected rates further from the center of displacement of the pontoonsections in one direction from the first position and toward the landbottom, and restraining movement of the sections relatively upwardly ofthe first position in a direction opposite said one direction while saidforce is applied between the hull and the pontoon sections,

continuing application of said force and moving thereby the hullrelative to the center of displacement of the pontoon sections furtherin said one direction toward the second position and into contact withthe land bottom while continuing said restraining movement of thepontoon sections while continually maintaining the pontoon sections withfreeboard to stabilize the barge,

and changing the magnitude of the controlled force in accordance withextraneous forces applied to the sections and changes in buoyancythereof during such submergence to vary the rate and attitude ofsubmergence of the hull to the underlying land bottom.

2. Method of operating a submersible barge as defined in claim 1including the step of adjusting the massbuoyance ratio of the mainsection to render the main section buoyant before application of saidforce.

3. Method of operating a submersible barge as defined in claim 1including the step of adjusting the massbuoyance ratio of the mainsection to render the main section non-buoyant before application ofsaid force.

4. Method of operating a submersible barge as defined in claim 1including the step of adjusting the massbuoyance ratio of the mainsection to render the main section slightly non-buoyant beforeapplication of said force.

5. Method of operating a submersible barge as defined in claim 1including the steps of adjusting the massbuoyance ratio of the mainsection to render the main section buoyant during the first period ofsubmergence of the hull to the land bottom and of adjusting themassbuoyance ratio of the main section to render the main 1 9 sectionnon-buoyant during the 1ast period of submergence of the hull to theland bottom.

6. Method of operating a submersible barge as defined in claim 1 inwhich said force is applied at a plurality of different points betweenthe main section and the pontoon sections.

References Cited by the Examiner UNITED STATES PATENTS Re. 24,346 8/1957Dawson 61-46.S 2,334,992 11/1943 Crake 61-46.S

' 2,525,955 10/1950 Scott 6146.5 2,528,089 10/1950 Siecke et a1. 61-4652,540,878 2/1951 Hayward 61-46.5 2,551,375 5/1951 20 Harris 61-465Wilson 61-46.5 Dawson 61-46.5 Dawson 61-46.5 Wolff 61-46.5 Suderow61-465 Dawson 61-465 FOREIGN PATENTS Great Britain. Italy.

OTHER REFERENCES World Oil, February 1, 1950, pages 108, 110 and 112.

Hayward 6146.5 15 EARL J. WITMER, Primary Examiner.

1. METHOD OF OPERATING A SUBMERSIBLE BARGE TO EFFECT SUBMERGENCE THEREOFTO THE UNDERLYING LAND BOTTOM OF A BODY OF WATER, THE BARGE BEING OF THETYPE HAVING A MAIN SECTION INCLUDING A FLOATABLE HULL CONNECTED TO ANUPSTANDING OPEN STRUCTURE SUPPORTING A PLATFORM SPACED ABOVE THE HULLAND A PAIR OF PONTOON SECTIONS LOCATED OUTBOARD OF THE MAIN SECTION ONOPPOSITE SIDES THEREOF WITH THE MAIN SECTION AND THE PONTOON SECTIONSBEING MOUNTED FOR RELATIVE INDIVIDUAL MOVEMENT IN UPWARD AND DOWNWARDDIRECTIONS TO DIFFERENT POSITIONS ALONG PREDETERMINED PATHS INCLUDING AFIRST POSITION IN WHICH THE CENTER OF DISPLACEMENT OF THE PONTOONSECTIONS IS AT SUBSTANTIALLY THE SAME LEVEL AS THE CENTER OFDISPLACEMENT OF THE HULL, A SECOND POSITION IN WHICH THE CENTER OFDISPLACEMENT OF THE PONTOON SECTIONS IS DISPLACED A MAXIMUM DISTANCEABOVE THE LEVEL OF THE CENTER OF DISPLACEMENT OF THE HULL AND SUCCESSIVEPOSITIONS FROM THE CENTER OF DISPLACEMENT INTERMEDIATE THE FIRST ANDSECOND POSITIONS, THE METHOD COMPRISING THE STEPS OF FLOATING THE BARGEON THE BODY OF WATER BY THE BUOYANCE OF THE PONTOON SECTIONS WITH THEHULL AND THE PONTOON SECTIONS IN THE FIRST POSITION AND EACH HAVINGFREEBOARD, APPLYING A FORCE OF CONTROLLED VARIABLE MAGNITUDE BETWEEN ANDONTO THE MAIN SECTION AND THE PONTOON SECTIONS AND BY SAID FORCE MOVINGTHE HULL AT SELECTED RATES FURTHER FROM THE CENTER OF DISPLACEMENT OFTHE PONTOON SECTIONS IN ONE DIRECTION FROM THE FIRST POSITION AND TOWARDTHE LAND BOTTOM, AND RESTRAINING MOVEMENT OF THE SECTIONS RELATIVELYUPWARDLY OF THE FIRST POSITION IN A DIRECTION OPPOSITE SAID ONEDIRECTION WHILE SAID FORCE IS APPLIED BETWEEN THE HULL AND THE PONTOOMSECTIONS, CONTINUING APPLICATION OF SAID FORCE AND MOVING THEREBY THEHULL RELATIVE TO THE CENTER OF DISPLACEMENT OF THE PONTOON SECTIONSFURTHER IN SAID ONE DIRECTION TOWARD THE SECOND POSITION AND INTOCONTACT WITH THE LAND BOTTOM WHILE CONTINUING SAID RESTRAINING MOVEMENTOF THE PONTOON SECTIONS WHILE CONTINUALLY MAINTAINING THE PONTOONSECTIONS WITH FREEBOARD TO STABILIZE THE BARGE, AND CHANGING THEMAGNITUDE OF THE CONTROLLED FORCE IN ACCORDANCE WITH EXTRANEOUS FORCESAPPLIED TO THE SECTIONS AND CHANGES IN BUOYANCY THEREOF DURING SUCHSUBMERGENCE TO VARY THE RATE AND ATTITUDE OF SUBMERGENCE OF THE HULL TOTHE UNDERLYING LAND BOTTOM.